Gene Symbol: exorh
Description: extra-ocular rhodopsin
Alias: ExR, exo-rod, rhodopsin, exo-rhodopsin, exorhodopsin, zfExR
Species: zebrafish
Products:     exorh

Top Publications

  1. Falcon J, Gothilf Y, Coon S, Boeuf G, Klein D. Genetic, temporal and developmental differences between melatonin rhythm generating systems in the teleost fish pineal organ and retina. J Neuroendocrinol. 2003;15:378-82 pubmed
    ..We review the fish pineal and retinal melatonin rhythm generating systems and consider the evolutional pressures and other factors which led to these differences. ..
  2. Ziv L, Tovin A, Strasser D, Gothilf Y. Spectral sensitivity of melatonin suppression in the zebrafish pineal gland. Exp Eye Res. 2007;84:92-9 pubmed
    ..Opsins-specific RT-PCR analysis confirmed the expression of exo-rhodopsin and visual red-sensitive opsin in the pineal gland, while other zebrafish visual opsins as well as VA and VAL ..
  3. Pierce L, Noche R, Ponomareva O, Chang C, Liang J. Novel functions for Period 3 and Exo-rhodopsin in rhythmic transcription and melatonin biosynthesis within the zebrafish pineal organ. Brain Res. 2008;1223:11-24 pubmed publisher
    ..The zebrafish opsin protein Exo-rhodopsin (Exorh) is expressed in pineal photoreceptors and is a candidate to mediate the effects of environmental light ..
  4. Vuilleumier R, Besseau L, Boeuf G, Piparelli A, Gothilf Y, Gehring W, et al. Starting the zebrafish pineal circadian clock with a single photic transition. Endocrinology. 2006;147:2273-9 pubmed
    ..One encodes the photopigment exorhodopsin and the other the melatonin synthesizing enzyme arylalkylamine N-acetyltransferase (AANAT2)...
  5. Appelbaum L, Gothilf Y. Mechanism of pineal-specific gene expression: the role of E-box and photoreceptor conserved elements. Mol Cell Endocrinol. 2006;252:27-33 pubmed
    ..Therefore, the mechanism identified for zebrafish aanat2, or at least part of it, may apply to other photoreceptor-specific genes in zebrafish and other species. ..
  6. Kojima D, Dowling J, Fukada Y. Probing pineal-specific gene expression with transgenic zebrafish. Photochem Photobiol. 2008;84:1011-5 pubmed publisher
    ..The zebrafish exorhodopsin gene encodes a pineal-specific photoreceptive protein, whose promoter region harbors a cis-acting element, ..
  7. Toyama R, Chen X, Jhawar N, Aamar E, Epstein J, Reany N, et al. Transcriptome analysis of the zebrafish pineal gland. Dev Dyn. 2009;238:1813-26 pubmed publisher
    ..Among the multiple candidate genes suggested by these data, we note the identification of a tissue-specific form of the unc119 gene with a possible role in pineal development. ..
  8. Tarttelin E, Fransen M, Edwards P, Hankins M, Schertler G, Vogel R, et al. Adaptation of pineal expressed teleost exo-rod opsin to non-image forming photoreception through enhanced Meta II decay. Cell Mol Life Sci. 2011;68:3713-23 pubmed publisher
    ..Our findings suggest that the requirements of non-image-forming photoreception have lead exo-rod opsin to adopt a characteristic that seemingly favors efficient bleach recovery but not at the expense of absolute sensitivity. ..
  9. Helvik J, Drivenes O, Naess T, Fjose A, Seo H. Molecular cloning and characterization of five opsin genes from the marine flatfish Atlantic halibut (Hippoglossus hippoglossus). Vis Neurosci. 2001;18:767-80 pubmed
    ..This work shows for the first time molecular isolation of a complete set of retinal visual pigment genes from a marine teleost and describes the first cloning of an ultraviolet-sensitive opsin type from a marine teleost. ..

More Information


  1. Morrow J, Lazic S, Dixon Fox M, Kuo C, Schott R, de A Gutierrez E, et al. A second visual rhodopsin gene, rh1-2, is expressed in zebrafish photoreceptors and found in other ray-finned fishes. J Exp Biol. 2017;220:294-303 pubmed publisher
    b>Rhodopsin (rh1) is the visual pigment expressed in rod photoreceptors of vertebrates that is responsible for initiating the critical first step of dim-light vision...
  2. Lu P, Lund C, Khuansuwan S, Schumann A, Harney Tolo M, Gamse J, et al. Failure in closure of the anterior neural tube causes left isomerization of the zebrafish epithalamus. Dev Biol. 2013;374:333-44 pubmed publisher
    ..This mechanism fails when the two sides of the epithalamus are widely separated from one another, suggesting that it is dependent upon a signaling protein with limited range. ..
  3. Sukeena J, Galicia C, Wilson J, McGinn T, Boughman J, Robison B, et al. Characterization and Evolution of the Spotted Gar Retina. J Exp Zool B Mol Dev Evol. 2016;326:403-421 pubmed publisher
    ..Of note the spotted gar expresses both exo-rhodopsin (RH1-1) and rhodopsin (RH1-2) in rods...
  4. Kokel D, Dunn T, Ahrens M, Alshut R, Cheung C, Saint Amant L, et al. Identification of nonvisual photomotor response cells in the vertebrate hindbrain. J Neurosci. 2013;33:3834-43 pubmed publisher
    ..Pharmacological inhibition of the visual cycle blocks PMR behaviors, suggesting that opsin-based photoreceptors control this behavior. These data represent the first known light-sensing circuit in the vertebrate hindbrain. ..
  5. Davies W, Zheng L, Hughes S, Tamai T, Turton M, Halford S, et al. Functional diversity of melanopsins and their global expression in the teleost retina. Cell Mol Life Sci. 2011;68:4115-32 pubmed publisher
  6. Morrow J, Lazic S, Chang B. A novel rhodopsin-like gene expressed in zebrafish retina. Vis Neurosci. 2011;28:325-35 pubmed publisher
    The visual pigment rhodopsin (rh1) constitutes the first step in the sensory transduction cascade in the rod photoreceptors of the vertebrate eye, forming the basis of vision at low light levels...
  7. Noche R, Lu P, Goldstein Kral L, Glasgow E, Liang J. Circadian rhythms in the pineal organ persist in zebrafish larvae that lack ventral brain. BMC Neurosci. 2011;12:7 pubmed publisher
    ..Expression of two pineal rhythmic genes, exo-rhodopsin (exorh) and serotonin-N-acetyltransferase (aanat2), involved in photoreception and melatonin synthesis, ..
  8. Chen H, Leung T, Giger K, Stauffer A, Humbert J, Sinha S, et al. Expression of the G protein gammaT1 subunit during zebrafish development. Gene Expr Patterns. 2007;7:574-83 pubmed
    ..in the developing retina, where its transcription overlaps with the photoreceptor cell-specific marker, rhodopsin (rho)...
  9. Bellingham J, Whitmore D, Philp A, Wells D, Foster R. Zebrafish melanopsin: isolation, tissue localisation and phylogenetic position. Brain Res Mol Brain Res. 2002;107:128-36 pubmed
    ..They might represent a separate branch of photopigment evolution in the vertebrates or they may have a non-direct photosensory function, perhaps as a photoisomerase, in non-rod, non-cone light detection. ..